Bird migration is one of the great mysteries of nature. The earliest recorded observations of bird migration were 3000 years ago, as noted by Hesiod, Homer, Herodotus, Aristotle and others. The Bible also notes migrations, as in the Book of Job (39:26), where the inquiry is made: "Doth the hawk fly by Thy wisdom and stretch her wings toward the south?" The author of Jeremiah (8:7) wrote: "The stork in the heavens knoweth her appointed time; and the turtledove, and the crane, and the swallow, observe the time of their coming."
Each
year, millions of birds leave the comfort of Africa and fly across deserts,
mountains and oceans. They fly north to Europe and Asia, where they build their
nests and raise their young. A few months later they undertake another great
journal to return to Africa.
They
fly north when it is spring and summer. There at that time, the sun is over
northern hemisphere. Spring and summer days in northern countries are much
longer than the nights. The sun may rise at 4am and set at 9pm north of the Arctic
Circle. The sun does not set at all in mid June. This gives the birds plenty of
time to look for insects to feed their young.
Sometimes
circumstances such as a good breeding season followed by a food source failure
the following year lead to interruptions in which large numbers of a species
move far beyond the normal range.
The
primary advantage of migration is conservation of energy. The longer days of
the northern summer provide greater opportunities for breeding birds to feed
their young. The extended daylight hours allow diurnal birds to produce larger
clutches than those of related non-migratory species that remain in the tropics
year round. As the days shorten in autumn, the birds return to warmer regions
where the available food supply varies little with the season.
During
the cold, dark months of the northern winter, few insects survive. With the
coming of warm, sunny days, insects hatch in large numbers. The resident birds
cannot manage to eat them all. This leaves plenty of insects for food for
migratory birds to eat and feed their young.
In
fresh water wetlands and seashores, tiny crustaceans also multiply in the
summer, and eventually there is abundant food for wetland birds.
Some
large birds such as White Stocks may follow landmarks along their route while
some small birds such as Nightingales migrate at night and may be guided by the
stars. Scientists continue to study migrating birds hoping to understand how
they make that amazing journey.
Migrating
does not only happen to Africa. Birds also migrate from southern Asia and
Australia to northern Asia; and from South and Central America for instance;
The Arctic Tern, a beautiful silvery seabird migrates from Arctic Circle in the
north all the way to the Antarctic in the south. A few birds migrate in other
directions: from the tropics to lands far in the south and back again.
In
Kenya, more than 100 species of birds migrate to Kenya from other continents.
Some of these stay in Kenya until they fly north again. Others continue their
migration to southern Africa while a few migrate to Kenya from Madagascar and
southern Africa.
Migratory
birds in Kenya include White Stocks, Plovers and Sandpipers, Barn Swallows and
Nightingales among many others. Usually Migrating birds follow directions
called flyways. In Kenya, flyways pass through the coastal and eastern
lowlands, the central highlands, the rift valley and Lake Victoria.
You
don’t need to be a birder to enjoy seeing migrating flocks. All you need is a
spirit of adventure, and enjoy being outdoors.
Have a
wonderful outdoor expedition.
Peter K.
Philip
Adventure Kenya camping safaris,
Natural
Track Safaris
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